A conventional vehicle air conditioning apparatus includes a blower that blows an air into an air flow passage and a door that adjusts the amount of air passing through the air flow passage. The blower is driven by a blower motor. The door is driven by a servomotor. Therefore, electrical components such as the servomotor and the blower motor are mounted on the vehicle air conditioning apparatus. Driving of those electrical components is controlled by an A/C ECU (air conditioner control device).
Two types of a DC servomotor with a potentiometer and a stepper motor are mainly used as the actuator. Along with the widespread use of the vehicle air conditioning apparatuses, it is general to standardize the electrical components and use the same kind of motors without mixing the DC servomotors with potentiometers with the stepper motors to reduce the costs. With an increase in the number of actuators attributable to the enhancement of functions, the number of wires and the weight are increased, and an assembling property is deteriorated. Therefore, in order to improve the ease of assembly and the like, systems in which a communication network of the vehicle is locally networked (communication) are also increasing.
However, with the reduction in the costs of the electronic components, in particular, the reduction in the costs of a microcomputer, an integrated system that drives multiple actuators may be inexpensive. In an integrated module of Patent Literature 1, most of the control circuits incorporated in the respective electrical components of the vehicle user interface unit, the air conditioning control unit, and the vehicle air conditioning apparatus are incorporated into the integrated module, and electric wires necessary for the integrated module are reduced from the air conditioning control unit. Even such an integrated module communicates with a host control device, and a standard actuator is driven by standard communication messages.
The performances required for respective doors for controlling a wind direction of the vehicle air conditioning apparatus are different from each other. For example, for a temperature control, an actuator with a high resolution stop precision is required in order to perform fine control. In addition, inside/outside air doors and blowing mode switching doors are required to have a high responsiveness (speed) for performing odor interruption and defogging. In general, a DC motor (direct-current motor) used for the vehicle air conditioning apparatus has a high torque and a high speed, but a resolution of the sensor is low. Also, the stepper motor is high in resolution, but low in torque.
In the integrated module disclosed in Patent Literature 1 described above, a door drive motor is controlled by the standard communication messages. Since the communication messages used for control are different between the DC motor and the stepper motor, only the same kind of drive motors can be used in the integrated module. Therefore, when one of the DC motor and the stepper motor is used as a standard product, there is a possibility that the functions required for the vehicle air conditioning apparatus and the doors are limited, such as sacrificing accuracy or sacrificing high responsiveness.